Sessions has been a target of Trump’s ire since he recused himself last March from the FBI’s investigation into Russia’s interference in the 2016 US election, following reports that he was not forthcoming during his Senate confirmation hearing about his contacts with Russian officials during the campaign.

Sessions’ recusal is a key point of frustration for Trump, who once reportedly asked why he couldn’t order “my guys” at the “Trump Justice Department” to do what he wanted.

When the Russia investigation began picking up steam last summer,so did Trump’s attacks on his hand-picked attorney general, whom he called “weak” and “beleaguered” in a string of tweets.

He also repeatedly suggested Sessions should replace Andrew McCabe as deputy FBI director. McCabe was forced out of the FBI earlier this year amid an internal investigation into his handling of the bureau’s investigation into Hillary Clinton’s use of a private email server as secretary of state.

On Wednesday, The New York Times reported that Sessions was weighing whether to fire McCabe over allegations of misconduct days before he’s set to retire.

Trump’s tweets last summer came soon after he acknowledged in an interview with The Times that he would not have nominated Sessions to be attorney general had he known Sessions would recuse himself from the Russia investigation.

“Sessions should have never recused himself, and if he was going to recuse himself, he should have told me before he took the job, and I would have picked somebody else,” Trump told the newspaper.

Sessions said over the weekend that he believed he made the right decision by stepping aside from the Russia investigation.

Robert Mueller, the special counsel leading the Russia probe, is believed to be focusing on the period last summer when Trump ramped up his attempts to pressure Sessions to carry out his suggestions. That inquiry makes up one thread of Mueller’s investigation into whether Trump sought to obstruct justice when he fired James Comey as FBI director last May.

The White House initially saidComey was fired because of the way he handled the Clinton investigation. But Trump later said on national television that he fired Comey in part because of “this Russia thing.” He also reportedly told two top Russian government officials that dismissing the FBI director had taken “great pressure” off of him.

After Comey’s firing, Deputy Attorney General Rod Rosenstein appointed Mueller as the special counsel in charge of the Russia investigation. Typically, such an appointment falls to the attorney general, but Sessions did not do so because of his recusal.

Should Sessions be fired, Trump is mulling replacing him with Scott Pruitt, the head of the Environmental Protection Agency, Vanity Fair reported.